A. This news story. Apparently satellite photos now confirm that
the polar ice caps are shrinking and the planet's temperature is
increasing. As more carbon dioxide is released into the atmosphere,
more of the sun's heat is getting trapped. If this keeps up, the global
climate change is likely to be dramatic.

Q. And you find that funny? What human beings are doing to the
planet is tragic!

A. What are human beings doing to Mars?

Q. Mars?! Who's talking about Mars?

A. I am. This article is about the erosion of the polar caps on
Mars, where the ice is made of carbon dioxide and the average
temperature is 81 degrees below zero. A little warming doesn't sound so
tragic to me. Though you might think it's a tragedy not to have anyone
to blame it on.

Q. Fine, go ahead, joke about it. I may not know know about Mars,
but I know that climate change will be a disaster here on earth.

A. I doubt it. Climate change is normal. We can handle it.

Q. Normal? What do you mean, normal?

A. I mean that change is not an aberration, it's the way the world
works. Look: A thousand years ago, the Northern Hemisphere was in the
middle of what's called the Medieval Warm Period. Temperatures then
were high enough that the Vikings could cultivate Greenland, which today
is covered with ice. By 1500, the climate pendulum had swung the other
way. The next few centuries were so cold that historians call them the
Little Ice Age. Oranges stopped growing in ChinA. Glaciers engulfed
French villages. Then in the 20th century, the world started warming up
again. Climate changes. It always has.

Q. But what's happening now is so alarming. Weather is going
haywire all over the world. Remember the Newsweek cover story on global
warming? It said, "The weather is always capricious, but last year gave
new meaning to the term. Floods, hurricanes, droughts -- the only
plague missing was frogs. The pattern of extremes fit scientists'
forecasts of what a warmer world would be like." You don't think that's
serious?

A. Of course hurricanes, floods, and droughts are serious. But
they're not occurring more frequently; it only seems that way because
the media have grown obsessed with bad-weather stories. Pro-Kyoto
activists attribute every extreme weather event to global warming. Back
in '96, when record lows were being set in the Midwest, Bill Clinton
even blamed the cold air on global warming! It's hype, not science.

Q. But Newsweek --

A. Hey, Newsweek is fine for some things. But if you want
information on climate change, you go to climate scientists. And they
say there's no evidence that weather is getting more intense.

Q. They do?

A. They do. "Overall, there is no evidence that extreme weather
events, or climate variability, has increased in a global sense through
the 20th century, although data and analyses are poor and not
comprehensive." That's a quote.

Q. From where?

A. Straight from Mount Sinai: the Intergovernmental Panel on Climate
Change. That's the United Nations panel whose reports are driving most
public policy on this issue. And what the IPCC says about global
warming and wild weather is pretty much the case for every other
sweeping claim uttered about global warming: The evidence just isn't
there.

Q. Okay, so maybe the activists go too far. But the earth is
warming up. That's not a sweeping claim. And the main reason is all
the carbon dioxide released by the fossil fuels we burn. That's not a
sweeping claim either.

A. Don't be so sure. Over the past century, surface temperatures
have climbed by about 1 degree. But in the lower atmosphere, where we
can measure temperatures very precisely by satellite, there hasn't been
any warming trend at all. Instruments on weather balloons show the same
thing. And yet the computer models that the gloom-and-doom scenarios
are based on say that the lower atmosphere must be warming up.

A. Why? Look how often TV forecasters get tomorrow's weather wrong.
Global climate is far more complex than local weather. Trying to
predict where that climate will be in 100 years is more complex still.
And the idea that disaster looms if we don't scale back our energy use
is just crazy. There are huge gaps in what scientists know about the
natural causes of climate change. By comparison with those, human
impacts are minor.

Q. What huge gaps?

A. Well, take clouds. Do they intensify warming by trapping heat or
diminish it by reflecting solar rays back into space? It's a huge
issue: Clouds cover 65 percent of the planet. But scientists just don't
know what their effect is. The IPCC says this is "probably the greatest
uncertainty" and a "significant source of potential error" in any
climate prediction. And that's only one of the big unsolved mysteries.
There is so much about climate change we just don't know. No wonder the
computer models keep getting it wrong.

Q. So we should do nothing?

A. We should tune out the alarmists. We should keep the human
effect in perspective. We should remember that climate change is
natural. Mostly, we shouldn't
panic.